1. Field of the Invention
The present invention relates to a mobile communication device and an antenna structure and, especially, to a dual-band mobile communication device and an antenna structure that is applicable to the wireless wide area network (WWAN) operation.
2. Description of the Related Art
Currently, most of the mobile communication devices use the GSM (Global System for Mobile Communication) system, but a third-generation mobile communication system, UMTS, (Universal Mobile Telecommunication System) has also gained popularity among users. Therefore, it is essential for the antenna of a mobile communication device to cover both the GSM and UMTS bands.
In order to cover the operating bands of 824˜960 MHz and 1710˜2170 MHz, the traditional antenna usually occupies a large space inside the mobile communication device. In the prior technology, the coupling feed is used to reduce the antenna size and still maintain the multiband operation of the antenna.
However, the arrangement of the traditional antenna with a coupling feed usually cannot effectively reduce the length of the antenna along an edge of a mobile communication device. Hence, the occupied area of the antenna cannot be further reduced. For example, a coupling feed method for a multiband mobile communication device is disclosed by Taiwan Patent NO. I295517. The internal multiband antenna disclosed by this patent covers four operating bands of GSM900/1800/1900/UMTS. However, with this traditional coupling feed method, it is difficult to include the five operating bands of GSM850/900/1800/1900/UMTS and also reduce the occupied area of the antenna.
Therefore, it is necessary to provide a dual-band mobile communication device and an antenna structure thereof, which will eliminate the problems encountered by prior technologies.